An OTP device is a non-volatile memory device capable of storing information even when power of a unit is turned off. Several structures such as a fuse type and an anti-fuse type have been proposed for the OTP device.
In an OTP device of a fuse type, for example, a large current may be applied to a resistive device formed of a material such as polycrystalline silicon to fuse a resistor, and thereby, a state between both electrodes is varied from a short (short-circuit) state to an open (open-circuit) state. Thus, the OTP device of a fuse type performs writing operation. On the other hand, in an OTP device of an anti-fuse type, for example, a voltage equal to or higher than a dielectric withstand voltage is applied to a capacitor of a metal oxide semiconductor (MOS) type to breakdown a dielectric film, and thereby, a state between both electrodes is varied from an open state to a short state. In other words, the OTP device of an anti-fuse type performs information writing operation by varying the state between the both electrodes from an open state to a short state.
Moreover, for example, Patent Literature 1 proposes an OTP device of an anti-fuse type that utilizes a technique different from the above-described technique.